This application claims the priority benefit of European patent application EP 00 122 808.9 filed on Oct. 19, 2000.
Not Applicable
The invention concerns a dosing dispenser for flowable media with a manually handled pump integrated in a medium container. In this context, flowable media are primarily fluid and pasty media. Such flowable media are, for example, cosmetic and pharmaceutical fluids, creams and ointments and also liquid and pasty media used in the medical sector, homecare and household, but also industrially used fluid cleaning detergents and the like.
A great number of hand-manipulated pumps are particularly known for the supply of pharmaceutical and cosmetic flowable media; they are, however, not integrated in a medium container in which the medium is stocked. Instead, they are produced as separate units and applied to the container after filling it in a separate handling step, e.g. by screwing-on, snapping-on, beading, curling and the like.
Furthermore, the well-known manually actuated pumps are normally built by a plurality of cooperating components of different materials, like springs, metallic ball valves, pistons, plastic body parts, seals made of elastomers etc.
An object of the invention is to provide a dosing dispenser for flowable media having a simple construction, as few components as possible and a pump which is integrated inside the medium container.
The dosing dispenser according to the invention comprises: an inner chamber for storing the medium, a piston which closes the container in a fluid-proof manner from the outside and which is slidingly movable in a guided manner between an upper position and a lower position within the container, a piston chamber being provided within the container bottom directly adjacent to and preferably below the inner chamber of the container and having an open upper end aligned to the piston, a connecting channel which extends within the piston in the sliding direction thereof and provides a fluid-communication to the outside of the container, a spring which urges the piston into its upper position, a sealing means which seals the opening of the connecting channel directed to the inner chamber of the container as long as the piston is in its upper position, wherein the piston in its upper position, is situated at a distance from the piston chamber and, during its downwards movement in its lower position, immerses into the piston chamber and closes the adjoining inner chamber of the container from the piston chamber.
In order to achieve the possibility for providing multiple dosages using the filled dosing dispenser, the piston chamber has less volume and generally a smaller cross-sectional area than the inner chamber or inner medium reservoir of the container. The inner chamber or reservoir directly adjoins the piston chamber and is preferably arranged above the piston chamber in order to guarantee that the medium automatically refills the piston chamber.
Apart from the fact that in the dosing dispenser, according to the invention, the pump is an integrated component of the medium container, and that the dispenser preferably only comprises a small number of plastic components, it also avoids the otherwise usual check or ball valves. The mounting of the dispenser is easy and does not take time. Although the pump is integrated in the dispenser, the form of the container may be of a great variety.
Furthermore, the dosing dispenser comprises one or more sealing elements, which, as long as the piston is in its upper position, close the inner opening or inlet of the connecting channel facing the inner chamber of the container. The opening of the connecting channel may be a transverse opening provided at a side wall of the piston and the sealing element may be formed by a longitudinal or axial wall section of the container.
If the opening of the connecting channel is an axial opening located at the lower end wall of the piston, the sealing elements preferably may comprise a sealing-plug protruding upwards from the bottom of the piston chamber, which engages into a widened lower section of the connecting channel.
The bottom of the container and the piston chamber integrated therein preferably form a separate unit. This makes the assembly of the dispenser and the filling of the container before mounting the bottom at the container easier.
Preferably, the spring is arranged in an area without media, i.e. an area isolated from the inner chamber of the container and the connecting channel of the piston. In this way, a contact between the spring, which may be produced for example out of steel, and the medium is avoided. This is especially significant for the medical sector where functional safety and purity of the components are indispensable.
Further constructive advantages regarding a better piston guidance result from guiding the piston in a particular longitudinal section. In this case, the spring may be arranged as a helical spring in an isolated axially extending spring chamber between the longitudinal section and the piston.
The spring may not only be a separate pressure spring, but also be provided in the form of one or several spring elements, which are formed in one piece with either the piston or the container in order to press the piston upwards.
A spray head protruding from the upper end of the container may be connected with the upper end of the piston, whenever spraying of the medium is desired.
If several media are to be dispensed, one or several partition walls may extend in longitudinal direction inside the container, which divide the inner chamber of the container and the piston chamber into two or more medium chambers which are isolated from each other in the upper or rest position of the piston.
The dosage ejected per actuation of the dispenser mainly depends on the volume of the piston chamber. The number of possible dosages may be adjusted by changing the volume proportion between the piston chamber and filled inner volume of the container. The discharge pressure depends on the cross section of the connecting channel extending though a major part of the piston and possible discharge channels connecting thereto.
In the following, preferred embodiments of the invention will be further explained with reference to the attached drawings.